广州地区鲍曼不动杆菌的多位点序列分型及流行克隆

Multilocus sequence typing and epidemic clones of Acinetobacter baumannii in Guangzhou area

目的本研究对广州地区5家教学医院的鲍曼不动杆菌进行分子流行病学分析。方法5家教学医院共采集138株鲍曼不动杆菌,利用多位点序列分型(multilocus sequence typing,MLST)及eBURST算法评价菌株之间的遗传关系。结果MLST将138株鲍曼不动杆菌分为8个已有序列类型(STs),分别为ST195、ST208、ST457、ST136、ST254、ST548、ST445和ST53,还发现17个新STs。其中ST195的数量最多,占所有分离株的35.5%(49/138),其次为ST208,占所有分离株的21.0%(29/138)。eBURST算法分析显示以ST195为预测祖先型的克隆复合体(clonal complex,CC)195在医院环境中广泛传播。结论鲍曼不动杆菌CC195是广州地区的流行克隆,各家医疗机构应根据其自身实际制定感染防控策略。

Objective We analyzed the molecular epidemiology of A.baumannii isolated from 5 teaching hospitals in Guangzhou to identify the epidemic clone in this area.Methods A total of 138 strains of A.baumannii were collected from 5 teaching hospitals,and the genetic relationship was evaluated by multilocus sequence typing(MLST)and eBURST algorithm.Results MLST divided 138 strains of A.baumannii into 8 existing sequence types(STs),namely ST195,ST208,ST457,ST136,ST254,ST548,ST445 and ST53,and 17 new STs.Among them,ST195 had the largest number,accounting for 35.5%(49/138)of all isolates,followed by ST208,accounting for 21.0%(29/138)of all isolates.eBURST algorithm showed that the clonal complex(CC)195,the predicted founder ST195,was widely spread in the hospital environment.Conclusion A.baumannii CC195 was an epidemic clone in Guangzhou area.Medical institution should develop infection prevention and control strategies according to its own actual conditions.